1. Field of the Invention
The present invention relates to an apparatus including a battery check circuit.
A battery check circuit is a circuit for detecting and indicating if a power supply battery has a normal voltage in order to assure that an electric circuit included in an apparatus, for example a camera, is capable of performing a normal function. It is spacewise and costwise advantageous to incorporate such battery check circuit into an integrated circuit element which includes a light-measuring circuit and a control circuit for the camera. However, as the number of external terminals of such integrated circuit element is limited, it is desirable that the power supply terminals for said battery check circuit can be used also as the power supply terminals for the above-mentioned other circuits.
2. Description of the Prior Art
FIG. 1 shows a conventional apparatus provided with power supply terminals used in common for both circuits, wherein a main circuit 2 comprising a light-measuring circuit, control circuit, etc, for a camera and a battery check circuit 3 constitute an integrated circuit provided on a substrate 1, said circuits 2 and 3 being connected to a power switch S1 and a power supply battery 5 through common power supply terminals 4a, 4b. Also connected to said battery check circuit 3 are a battery check switch S2 through terminals 6, 7 and a display element 8 through a terminal 9. Such arrangement is inconvenient for actuating the battery check circuit 3 since the battery check circuit can be operated only after the power switch S1 for the main circuit is closed. For example in case of a camera wherein the power supply switch to the light-measuring circuit, etc., is closed by pulling out a film winding lever, the battery check switch can be operated only after said winding lever is pulled out by a predetermined angle.